1. Field
Certain aspects of the present disclosure generally relate to wireless communications and, more particularly, to scheduling methods for cooperative beamforming.
2. Background
Coordinated multi-point (CoMP) is being considered as a key enabler of high spectral efficiency requirements set forth by the Long Term Evolution Advanced (LTE-A) standard. A common utility-based framework has been proposed in the LTE-A standard to handle downlink cooperative transmission across cells, resource partitioning in heterogeneous deployments, as well as user equipment (UE) association in a unified fashion. There are two key elements in the proposed framework: a notion of projected utility and a real time coordination of scheduling decisions across cooperative cells.
The notion of projected utility accounts for spectral efficiency, backhaul capacity and latency, channel state information accuracy, UE scheduling priority in terms of Quality of Service (QoS)/fairness as well as UE and network capabilities. Calculation of the projected utility based on inter-cell information exchange over the backhaul may not always lead to accurate coordination of scheduling and transmission decisions. This applies, in particular, to Wireless Wide Area Network (WWAN) deployments with a generic Internet Protocol (IP) backhaul and/or home eNodeB (HeNB) deployments with the standard consumer backhaul. In such scenarios, over-the-air signaling may be required to achieve efficient real-time scheduling coordination.